Montresor leads Fortunato to the lowest part of the catacombs. Fortunato walked into a room thinking this is where he thought the Amontillado was. Montresor worked quickly and trapped him with chains and a lock. Fortunato struggled drunkenly but ended up passing out. This gave Montresor time to wall Fortunato up in the small room he as in.
Fortunato woke up to Montresor's wall all the way up but a small hole. They began speaking to one another. Sadly Fortunato realizes that Montresor is not joking around and he is forever stuck.
Half a century later (50 years) Montresor is not caught and feel little not remorse about his actions.